package org.eclipse.jdt.internal.jarinjarloader;

import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;
import java.util.jar.Attributes;
import java.util.jar.Manifest;

public class JarRsrcLoader {
	@SuppressWarnings({ "rawtypes", "unchecked" })
	public static void main(String[] args) throws ClassNotFoundException,
			IllegalArgumentException, IllegalAccessException,
			InvocationTargetException, SecurityException,
			NoSuchMethodException, IOException {
		ManifestInfo mi = getManifestInfo();
		ClassLoader cl = Thread.currentThread().getContextClassLoader();
		URL.setURLStreamHandlerFactory(new RsrcURLStreamHandlerFactory(cl));
		URL[] rsrcUrls = new URL[mi.rsrcClassPath.length];
		for (int i = 0; i < mi.rsrcClassPath.length; i++) {
			String rsrcPath = mi.rsrcClassPath[i];
			if (rsrcPath.endsWith("/"))
				rsrcUrls[i] = new URL("rsrc:" + rsrcPath);
			else
				rsrcUrls[i] = new URL("jar:rsrc:" + rsrcPath + "!/");
		}
		ClassLoader jceClassLoader = new URLClassLoader(rsrcUrls, null);
		Thread.currentThread().setContextClassLoader(jceClassLoader);
		Class c = Class.forName(mi.rsrcMainClass, true, jceClassLoader);
		Method main = c.getMethod("main", new Class[] { args.getClass() });
		main.invoke(null, new Object[] { args });
	}

	@SuppressWarnings("rawtypes")
	private static ManifestInfo getManifestInfo() throws IOException {
		Enumeration resEnum = Thread.currentThread().getContextClassLoader()
				.getResources("META-INF/MANIFEST.MF");
		while (resEnum.hasMoreElements()) {
			try {
				URL url = (URL) resEnum.nextElement();
				InputStream is = url.openStream();
				if (is != null) {
					ManifestInfo result = new ManifestInfo(null);
					Manifest manifest = new Manifest(is);
					Attributes mainAttribs = manifest.getMainAttributes();
					result.rsrcMainClass = mainAttribs
							.getValue("Rsrc-Main-Class");
					String rsrcCP = mainAttribs.getValue("Rsrc-Class-Path");
					if (rsrcCP == null)
						rsrcCP = "";
					result.rsrcClassPath = splitSpaces(rsrcCP);
					if ((result.rsrcMainClass != null)
							&& (!result.rsrcMainClass.trim().equals("")))
						return result;
				}
			} catch (Exception localException) {
			}
		}
		System.err
				.println("Missing attributes for JarRsrcLoader in Manifest (Rsrc-Main-Class, Rsrc-Class-Path)");
		return null;
	}

	@SuppressWarnings({ "rawtypes", "unchecked" })
	private static String[] splitSpaces(String line) {
		if (line == null)
			return null;
		List result = new ArrayList();
		int firstPos = 0;
		while (firstPos < line.length()) {
			int lastPos = line.indexOf(' ', firstPos);
			if (lastPos == -1)
				lastPos = line.length();
			if (lastPos > firstPos) {
				result.add(line.substring(firstPos, lastPos));
			}
			firstPos = lastPos + 1;
		}
		return (String[]) result.toArray(new String[result.size()]);
	}

	private static class ManifestInfo {
		String rsrcMainClass;
		String[] rsrcClassPath;

		private ManifestInfo() {
		}

		ManifestInfo(ManifestInfo paramManifestInfo) {
			this();
		}
	}
}